Pyrometer.



G. B. THWING.`

PYROMBTBR. APPLICATION FILED JULY 9, 1907.

Patented .27,1909.

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PYROMETEB..

.1\.1=1 L10A'1210Nv FILED JULY 9. 1907.

919,399, Patented m2211909 2 SHEETS-SHEET 2.

l@ Avr/N TOR I I Alorney pyronieters, and consists incertain improve-Philadelphia, in

CHARLES B. THWING, O F PHILADELPHIA, PENNSYLVANIA.

PEROEEETER.

Tool! whom tt may concern: A 4 Be it known that I, CHARLES B. THWING, acitizen of the United States, residing at and' State of Pennsylvania,have invented a new and useful "Improvement in Pyrometers,

of which the following is a specification.

My invention relates to thermo-electric ments in the thermo-electriccouple and also 1n the galvanom'eter usedtherewith, which greatlyincrease the range and convenience of use of such instruments Myimproved thermoelectric couple is designed to indicate the temperatureof 'a' v distant hot body by means of absorbed radia tions of heat whichare transmitted tothe junction of the couple, the parts of the ap'-paratus being so designedthat it will, without .focusing orotheradj'ustmentl indicate lcorrectly the temperature of such bodyregardless of'the distance of the same therefrom, so-long as ythesurface whose temperature is to be measured Iis large enough to -ll thefield or angle'of view of the 'tube of the device.

The galvanometer which -I have devised 't'o'r' use with my improvedcouple consists ot' a vcoil which is adapted to vibrate between twopolepieces,.said pole' piees bein attached respectively to the north ands th poles of a pair of magnets, each pole piece l connecting` likepoles of the two magnets.

When the pole pieces are true segments. of a circle and are so shaped astoprovide an air ,gap of uniform distance between them at all points,equal increments of electro-motive force will produce equal increase intheudelectlon ot the coll.V Equal increment-s of temperature, however,do 'not produce, 1n

general, equal increments of electro-motive tion of my 'improvedthermo-electriccouple andthe 'devices for -force in the pyrometer. Myimprovement in the galvanometer relates to means vby which the scale oftemperatures indicated 45.

by the couples is made a In the drawings, specification,

scale of equal arts. .forming part o. this Figure l 1s a longitudinalseogathering and concentrating the heat radiations'thereon. .FigJQ is anenlarged detached-sectional view of the couple and themountingltherefor. Fig.

of a modilication, showinga cluster. of

couples. 4 isa View similar to Fig. l,

VSpeeflcation of Letters Patent. Application filed. July t), 1997.Serial No. 382,878.

the county of Philadelphia heat radiations.

also on an enlargedy scale,

'. showing a modification of the devices forl Patented April 27, 1909.-l

gathering and concentrating the heat radia-v tions. Fig. is 4a view ofmy lmproved galvanometer for measuring the current generatedby'thecouple. F ig. -is a Vertical section on the line VI -VI of Fig. 5. Figs.7 and S are detail views showing modified forms of the pole-pieces ofthe galvanometer.

Like symbols of reference indicate like I parts in each.

In the drawing, 1 1s acasing or tube,

blackened on its vinner surface'4 to absorb v 21 is a funnel-shaped tubeof reflect-ing .materiah preferably. circular in cross-Section', asshown in Fig. 1', al-Y though it maybe made square. 1nI crosssection, asshown in Fig. 4, or it 4may be v made with` only7 two converging sides.The casing or tube lmay also be made square in cross-section ifpreferred. The reHector 2, byv a series or succession of reflections,concentratesthe radiations of hea't gathered by the tube 1 upon thejunctionof a ther1no-electric couple 4', 4', as in Figs'l and 2, or thejunctions of a cluster of such'couples, as in Fig. 3, the negativeelementof which, in each case, is composed,

preferably,'of an alloy consisting of about i '40 parts nickel and 6()parts copper, and

the positive element being composed, preferably. of iron. The advantageof uslng funnel-'shaped ,reflector 2,.instead of a concave mirror or alens is that such reector 1s equally 1n focus. for rays from vanydistance, thus rendering'it unneces- `Sary to adjust or focus theinstrument.'

To the elements 4, 4', are connected the vgalvanometer-leads 5, 5. Inthe rear of the junction 'of the couple or couples, is placed a smallplane mirror 3, to catch and pass said junction, thus increasing thepower .of the instrument while maintain` ing the constant focus. 6 is aninsulating support, having integral projections 6 extending from theface thereof, between which projections the ele- 'ments 4,- 4', y arecemented or -otherwise tired, said elements-'being connected to'-gethe'r at theirinner ends, the positive end 'ot each couple,I intheform shown in Fig. 3,-

being connected atits outer end to the outer .endet the negative elementof the adjoin'- -ing couple.

The main body portions' of the positive and negative el'g-anents in Fig.

.send 'back such of the radiations 'as may siz'e of, the opening intothe tube may be' 1g varied or adjusted, said diaphragm being held inposition' by means of a shoulder on the cap 10 which isscrewed upon theend of the tube 1. By removingthe j cap 10, the size of the diaphragmmay be e-hanged, or a diaphragm of another size subst1tuted,'until thereading of the instrument agrees with that of a standard exposed to thesame temperature.

In `Fig. (t I show a modification by means 20 of which the instrumentmay be adapted to y tworangesoftemperaturewith onetube. `In saidiigurenthe tube l isicomposed of two telescoping sections, 1, 1',theinner section 1', being provided with a groove into which g5 extendsa spring a connected to the outer sectionl. When the two sections are intheir', closed position the instrument isy set "for the lower range oftemperatures, and `\when in their extended position it is set yr thehigher range. The galvanometer which I use in connection with myimproved couple is shownin Figs. 5, 6, and 7. It consists of a pair ofma tac ed to them the pole-pieces 12, 13, between Whichpole-pieees isthe air a 14 -in which vibratesthe coil 15 mounte 1n suitable bearings16, and having attached to it the pointer 17. The parts are inclosed ina 40 casing 18, and the instrument is provided with an indicating scale19. As before stated, when thepole-pieces` 12 and 13 are truev se mentsof a circle, as indicated by the dottedines in Fig. 7 and are so shapedas 45 to leave the air gap 14 of uniform distance between them at alloints, as represented by the dotted line in ig. 8, equal increments ofelectro-motive force will produce equal increase in the deflection ofthe coil. But as before stated, e ual increments of tcmperature do notpro uce, in general, equal increments of electro-motive force. I providefor this variation and make the scale ottemyperatures indicated bythecouple a scale of equal parts in one of two ways, vim-as shown in Fi 7,where the pole pieces are changed in s ape, as shown 1n full lines so asto vary the length ofthat portion of the' coil which traverses the fieldof magnetic ooi force at different parts of the scale;--or, as shown inFig. 8, where the widthot` the air gap 14 changes in different parts ofthe scale, thus varyin the intensity of the magnetic field inverse ywith the varying electro-moe5 tive force, and again permitting of a'uniets 11 the poles of which have at form scale; By the'se rtiea ns thesame printed scale may be used fora' variety-of couples,

and the instrument adjusted to correspond to each of the-cou les.'- Theforms of polepieces shown by t e dotted lines in Figs. 7 470 and 8 are`:for uniform electlo-not-ive forces; the forms shown by the full linesfor use' with a couple giving larger electro-motive forces at highthauat low temperatures.

The operation of-my improvement is as' 7.5 follows :-V-The end 10' 'ofthe tube or casingV 1 is plointcd at the bot body the tem eraturo of wich is to' be'measurech'the on y neces-v sary requirement heini that thesurface whose temperature is to e measured shall be su large ,enough tofill the field of view of the tube. The heat radiation .from the hotbody entering the end of the tube will be reflected in a series ot'reflections by the reflectorQ, and finally will Abe converged'orconcen-"as tratcd upon the junctions of the couples 4, 1'. By `thismeans a current of electricity y is generated, corresponding to thevariations in temperature .between the hot and cold ends of the couples,said current being trans-.90 mitted to the fralvanometer, Where 1toperates in the orcinary manner." All that is required in the` operationof the device is a surface six inches in diameter at a distance of feetfrom the obseryers hand, 3 inches 951 diameter at 3 feet, and otherdistances in proportion. So long as the body-whose temperature is to bemeasured exceeds these dimensions the distance makes no'variation in thereading ol` the instrument. No focus-v 10o ing or estimatou'io'fdistance is required.- lu two seconds after the tube is pointed at .thehot surface its temperature is indicated on the scale of thegalvanolneter. Thus, a single instrument w1ll serve for taking the 105temperature oi a large number of furnaces, crucibles. or kilns, in anexceedingly brief period of time.

1. ln a pyromcter, a tube or casing having an inner nonreflcclingsurface and an openingl at its outer end, a thermo-electric couple althe inner end of the tube or casing, a relzctor in said casing between'said outer end and the saidcouple and adapted to concen- 11.5 trate theheat radiationscntering said tube upon the junction of said couple.

L. ln a pyroineter, a tube ,or casing having an `inner nou-re{lectingsurface and having au opening at its outer cud, a thermo-elec- ,iriecouple at the inner end of said tube a fnnnel-slmped reflector havingits larger end directed toward said outer end of the tube audit smalleren'd toward the said couple and adapted lo concentrate the heatradiations eutcringsad tube upon the junction of said couple. i

3. ln a pyro1neter,a tube or casing having an inner nonfrcllmelingheat-absorbmg surface'aud an opening at its outcr end, a 130thermo-electric couple at the inner end' ofthe tube or `using, a.reflector in said casing between said outer end and the said couple andadapted to concentrate the heat radiations entering said tube andgathered by said lient-absorbing surface upon the junction of smidcouple, and a Second plane reflector in the renr of said couple adaptedto catch the heat rays passing said junction and throw themy back uponthe junction of the couple.

4. lh zt pyrometer; a tube or casing having nn inner non-reflectingsurfaoe and an opening' :it its outer end7 :1 cap connected to saidoxter end, a diaphragm between ,the cap and the outer end of the tube, athermo-electric couple at, the inner end of the casing, and aconcentrating reflector in said casing between its outer end and thethermoelectric couple and adapted to concentrate the heat radiationsgathered by said casing upon 'the its outer end and thethermo-eleotriccou 1e` i und adapted to concentrate the 'heat radlationsgathered by said tion of said couple.

In testimony whereof I my hand.

casing upon the junc- GHARLES B. THWING. VVitnesseS: v

Crus. SANDER, IC. Ans'rron.y

have kerelum;v set-

